1. FIELD OF THE INVENTION
The invention relates to passive optical radiation direction finding generally, and more specifically to such devices operative on substantially a single burst of optical energy to determine angle of incidence and wavelength of the received optical radiation.
2. DESCRIPTION OF THE PRIOR ART
In the prior art optical direction finding has been accomplished variously. One particular prior art device, according to German patent No. DE-OS 25 11 016, utilizes a battery of objective lenses distributed about a convex surface, each lens having its optical axis directed at a different angle. The received ray bundles are redirected via mirrors or prisms onto an image plane and projected therefrom via additional lens systems to individual optical detectors. The spatial angle covered by each of said objective lenses is relatively large and, accordingly, only an approximate angular determination of received radiation is achieved. Moreover, the mechanical construction of such a device is expensive in view of the complex optics and the large duplication of amplifiers and multiplexers required.
The manner in which the invention addresses the problem, resulting in a highly advantageous arrangement, will be understood as this description proceeds.